Bumetanide and furosemide in heart failure

Area of Science:

• Pharmacology
• Nephrology
• Cardiology

Background:

• Congestive heart failure (CHF) often leads to diuretic resistance.
• Understanding the pharmacokinetics of oral diuretics in CHF is crucial for effective treatment.

Purpose of the Study:

• To compare the handling and response to oral bumetanide and furosemide in patients with stable congestive heart failure (CHF).
• To examine differences in drug handling and response between CHF patients and normal subjects.

Main Methods:

• Oral administration of bumetanide (1.0, 2.0 mg) and furosemide (40, 80 mg) to 20 CHF patients.
• Comparison of drug absorption, peak concentrations, elimination half-life, and dose-response curves between drugs and with normal subjects.

Main Results:

• CHF patients exhibited prolonged absorption and lower peak concentrations of both bumetanide and furosemide compared to normal subjects.
• More bumetanide than furosemide was absorbed in both groups.
• Elimination half-lives were longer in CHF patients; furosemide's half-life was approximately twice that of bumetanide.
• Dose-response curves were shifted downward in CHF patients for both drugs.
• Overall response to bumetanide and furosemide did not differ significantly in CHF patients.

Conclusions:

• Oral bumetanide and furosemide show similar clinical efficacy in CHF patients, despite pharmacokinetic differences.
• Delayed absorption and altered tubule responsiveness in CHF contribute to diuretic resistance, not malabsorption.
• Peak diuretic excretion rates were significantly lower in CHF patients compared to normal subjects.